The popularity and use of mobile terminals or mobile telephones has skyrocketed over the past 20 years. Although variations exist, many of these devices include some form of input device, such as a keypad, a QWERTY keyboard, etc. Furthermore, these devices are often designed to be used or operated in a variety of different lighting environments, such as indoors, under incandescent or fluorescent lighting; outdoors in direct sunlight; in the dark, etc. Accordingly, visibility of keys or key identifiers may differ, based on the light conditions in which the device is to be used.
Known keyboards and keypads typically include either printed key identifiers or backlit keys. With printed key identifiers, no light source is used to facilitate viewing of the keys in dark environments. Conversely, backlit keys or keypads typically use some form of light source to light up the key identifiers for at least a predetermined period of time. Unfortunately, existing backlighting systems may result in key identifiers lacking sufficient contrast for efficient viewing in high light environments.